A New Model for Infrastructure Service Life With Applications to Bridge Assessment and Management

Abstract

Service life is a critical, yet somewhat nebulous consideration in the management of infrastructure assets. Although often defined in terms of deterioration and time to physical failure, infrastructure service life is also defined by nonphysical factors such as increasing loads and alternate levels of evaluation. A new conceptual model is presented defining infrastructure service life as a function of physical and nonphysical factors. The model reflects, for example, the idea that an asset can be evaluated at different performance levels, with accompanying trade-offs in moving from a lower level to a higher one. In addition, the model recognizes that alternative performance evaluation techniques can influence a decision maker's perception of serviceability and remaining service life. Several applications illustrate how the model offers a fresh perspective on bridge service life, a key consideration given the trend toward ever-increasing truck loads. Results described have various implications for policy making and infrastructure asset management.